In a remarkable scientific breakthrough a team of scientists at Wake Forest University have used a combination of living cells and a special gel to print out living human body parts.
The technique which combines the use of plastic moulds and tissue cells can reportedly print out human organs such as ears, muscles and jawbones. The new research is already seen as an advance on previous attempts, which either involved making a plastic scaffold and then trying to get cells to grow in and on it, or a printed out organ shape that ends up being too floppy and subsequently dying.
Scientists say the new approach mixes live cells with a gel that starts out as a liquid but quickly hardens to the consistency of living tissue, and layers them in with tiny tunnels that serve as passages for nutrients to feed the cells until blood vessels can grow in and do the job naturally.
According to Dr Anthony Atala the lead researcher on the study team: “Our team are actually printing the scaffolds and the cells together.” “We show that we can grow muscle. We make ears the size of baby ears. We make jawbones the size of human jawbones. We are printing all kinds of things.”
Meanwhile his team have described the process of both the new ‘bioprinting’ technology, and the organs they have been able to grow using it, the excited team say: “We present an integrated tissue-organ printer (ITOP) that can fabricate stable, human-scale tissue constructs of any shape.” “The correct shape of a tissue construct is obtained from a human body by processing computed tomography (CT) or magnetic resonance imaging (MRI) data in computer-aided design software.”
The news of the latest breakthrough has been deemed a success by Atala and his team as they have been working for more than a decade in order to make grow-your-own organ transplants. However Dr Atala has described the challenge as difficult saying that living body parts are hard to replicate. Dr Atala explained: “It’s not enough to make, say, a heart-shaped blob of tissue. Even a simple structure, like an ear, has several types of cells and they must all be fed by tiny capillaries” “What happens if you don’t have them is the surface gets fed but if you make them any larger the central core with not get fed and they will die.”
Atala also revealed he and his team started out with actual inkjet printers but they’ve now developed customized devices. Explaining: “We started working with the printers about 12 years ago, trying to design printers specific to human tissues,” he said. “Nature itself gives us this limit where you cannot really print tissues in volumes larger than 200 microns.” Anything thicker and the cells on the inside die. “Because the cells need vital nutrients. as we print the cells we can create microchannels. It’s like a highway, within 24 hours, blood vessels start to sprout in these microchannels.”
Atala went onto say the second challenge is getting the bioprinted material to take on the right consistency at the right time. “You want the cells to go through the nozzle as a liquid. But you don’t want it to land as a liquid because it will just make a blotch. You want it to land like a gelatin,””Then as it hardens you want about as hard as a gummy bear.” The result is a mixture of polymers, living cells and the nutrients they need. “We call it bioink.”
Meanwhile the team also revealed they are currently exploring the possibility of printing out livers, lung tissue and kidney tissue. Although they did say the new technique is still years away from being used in actual human patients, but Dr Atala hopesit will be seen as a way for people to get custom-made transplants using their own cells, or closely matched cells, grown to just the right size and shape.